City Center Walk
Important landmarks to mention: House-Museum of Surikov on Lenina street, famous Russian painter who grew up in the city. He is mostly famous for the large scale historical paintings such as "Morning of the Strelets Execution".
Next place to mention is Tschasy (the clock-tower), which is currently a symbol of the city and could be found on 10 rubles note. Address: 110, Prospekt Mira. On the same square there is a Lenin Statue as well.
There are many restaurants, cafes and shops along these streets. At one point there are even palm trees (which are taken out in summer) in a little square near Gostiny Dvor hotel - a nice place to sit and watch people. Some sections of the street are paved and there are trees on both sides, making it a pleasant place to walk around.
If you get tired - finish the walk by relaxing a bit in the central park: there are a lot of benches there to have a little picnic.